I have a weird problem that recently started (still need to figure out exactly when) in a project using Kotlin 1.2.20 / 1.2.21, Gradle 4.4.1 / 4.5, and kotlintest 2.0.7. For some reason, IntelliJ does not hit breakpoints anymore, but only on Windows: All breakpoints say “Breakpoint does not belong to any class”. The exact same project still works on Linux. I already tried several times to re-import the Gradle project from scratch, but still no go.

Thanks for the hint, but I’ve already done git clean -fdx (which deleted .gradle in the project dir) and re-imported the project from scratch without any luck. Also, I don’t have the global Gradle build cache enabled for this project.

No, the versions are in sync and no warning is displayed. Meanwhile I has the chance to verify that debugging the project works on another Windows machine. So something must be corrupted in my setup, but I’m clueless what to delete in order to fix that.

Are you running it with gradle or IDEA runner? Idea has a separate code cache. Invalidate/restart usually helps, but not always. Also I had some bizarre things happening with Java 9 JDK, I had to roll back to JDK 8.